1. Field of the Invention
This invention relates to a substrate treating method for treating, e.g. cleaning, substrates such as semiconductor wafers or glass substrates for liquid crystal displays (hereinafter called simply substrates) with treating liquids such as a chemical solution and deionized water.
2. Description of the Related Art
Conventionally, this type of apparatus includes, for example, a treating tank for storing a treating liquid and receiving substrates, and a nozzle for supplying isopropyl alcohol (IPA) gas to an upper space in the treating tank (see Japanese Unexamined Patent Publication H10-22257 (paragraphs “0024” and “0025”, and FIG. 3), for example). With this apparatus, after supplying deionized water to the treating tank and cleaning substrates, IPA gas is supplied to the upper space in the treating tank to form an IPA atmosphere therein. Then, the substrates are pulled up from the treating tank to complete cleaning treatment of the substrates with deionized water. By pulling up and moving the substrates in the IPA atmosphere, the deionized water adhering to the substrates is replaced with IPA to promote drying of the substrates.
The conventional apparatus with such construction has the following drawback.
The conventional apparatus can promote drying by pulling up the substrates cleaned with deionized water out of the deionized water, and moving the substrates in the IPA atmosphere. However, there is a drawback that the pattern formed on the surface of each substrate can collapse.
That is, the pattern on the substrate surface collapses due to the surface tension of the deionized water on the substrate pulled up.
In the latest semiconductor devices, particularly in the field of memory, capacitors constructed in a cylindrical shape have begun to be employed as a technique for drastically increasing the degree of integration. Such a cylindrical structure has a very high aspect ratio, and a capacitor portion of cylindrical structure collapses easily during a manufacture process. Naturally, a collapse of the capacitor portion renders the device defective, and thus lowers yield.
It is conceivable to reduce the chances of collapse of the pattern by replacing the deionized water in the treating tank with a liquid with low surface tension, after the substrate cleaning with the deionized water in the treating tank noted above, and then pulling up the substrates from the treating tank and drying the substrates. However, the deionized water having entered minutia of the patterns on the substrate surfaces can remain without being fully replaced. It is thus impossible to eliminate collapse of the patterns formed on the substrates completely.